Estrogenic activity of hydroalcoholic extract of Clitoria ternatea Linn. leaves on rats

Objective: To assess the estrogenic activity of hydroalcoholic extract of Clitoria ternatea leaves in female Wistar rats. Methods: Hydroalcoholic extract of C. ternatea leaves prepared by using cold maceration method was tested for estrogenic activity. An acute toxicity study was conducted to estimate the safe dose using OECD 423 guidelines. For estrogenic activity, ovariectomized female rats were divided into four groups, with 6 rats in each group. The control and standard groups were administered with 1% carboxymethyl cellulose orally and estradiol valerate at 1 μg/rat/day subcutaneously, respectively. The third group was administered with hydroalcoholic extract of C. ternatea at the dose 500 mg/kg body weight orally and the fourth group was administered with hydroalcoholic extract of C. ternatea at the dose 500 mg/kg body weight orally along with estradiol valerate at dose 1 μg/rat/day subcutaneously. All treatments lasted for 7 consecutive days and estrogenic activity was assessed by observing vaginal cornfication. On day 8, all animals were sacrificed and uterine horns were dissected out. Utrine weight was measured and blood serum was further processed for the estimation of biochemical parameters like cholesterol, total proteins, alkaline phosphatase and estrogen by autoanylser. Histological studies of uterus were also carried out. Results: Acute toxicity studies indicated the hydroalcoholic extract of C. ternatea leave was found to be safe up to the dose level of 2 000 mg/kg. Oral administration of C. ternatea extract at the dose 500 mg/kg body weight and and estradiol valerate (1 μg/rat/day) caused morphological changes i.e. increase in uterine weight, vaginal opening and cornification of cells; biochemical changes i.e. increase in cholesterol, total protein, alkaline phosphatase and estrogen contents; histological changes i.e. increase in uterine diameter, thickness and height of endometrium. Simultaneous administration of C. ternatea extract with estradiol valerate showed a synergistic effect. Histological investigations further confirmed the strong estrogenic nature of C. ternatea extract. Conclusions: C. ternatea extract (500 mg/kg) showed a significant estrogenic activity which is also supported by biochemical and histological studies. So, on the basis of these findings, it can be concluded that C. ternatea can be used as an alternative to synthetic oral contraceptives.